A cluster is a group of individual servers, or nodes, configured to appear as a single, virtual server, to both users and applications. The nodes are physically connected by cables and programmatically connected by clustering software, such as Microsoft's Cluster Server™ and Microsoft's Failover Cluster™. The clustering software may run on each node and manage all cluster-specific activity. The cluster nodes may be attached to one or more shared disks by a shared bus. The clustering software differentiates between the shared disks by using a disk identifier stored on the disks themselves.
If a cluster node attempts to connect to a disk having the same disk identifier as a shared disk currently connected to another node in the cluster, such as a backup or snapshot of an existing disk on the cluster, the clustering software will be unable to differentiate between the two disks, rendering the new disk inaccessible. Thus, there may be a need for enabling a disk to be added to a cluster as a shared resource when the disk has the same disk identifier as an existing shared disk resource on the cluster.